Bordering
states dataset -- 100 mile option. This is a database of states
and their bordering states. If there are two towns in each states
that are 100 miles from each other, the states are considered
to be bordering.

Unambiguous first names. If you have a database of people's names but no gender field, this database of 970 unambiguous first names will give you a start for marking gender correctly in your database.